Question about Pump Saver

[RichardinTexas]

About a week ago we ran out of water. Our holding tank was empty so I checked the well pump and it would turn on and pump water for 2-3 seconds before the centripro pump saver would switch it off. Not enough to make it to the holding tank. It seemed to me that it was just drawing down and that our well was basically dry. We've been in a drought and I knew it wasn't producing much water.

So the well service technician came out to look at it and he thought it might be a leaking pipe because he said the pump saver was not turning off the pump (although it definitely was before he came out) and the pump tested fine. So he recommended pulling the pump to find out but the next day the owner called and said that wasn't the problem and the pump is just hanging in the air. He says we aren't the first in our area to go dry and recommended saving the money and wait for rain.

I think the owner is probably correct but my question is why would the pump saver stop turning the pump off after the technician came out? I know he opened up the top of the well, could that have changed something? I don't know exactly how the pump savers detect when the water level drops below the pump.

It would suck to spend the summer waiting for rain only to find out the well was never actually dry.

 

[Reach4]

why would the pump saver stop turning the pump off after the technician came out? I know he opened up the top of the well, could that have changed something? I don't know exactly how the pump savers detect when the water level drops below the pump.

Such units detect the drop in current when not pumping water vs pumping water. The units get adjusted/calibrated to a pump. If the calibration was on the edge, it could go either way.

You might want to get a clamp-around ammeter to see the pump current in different situations.
When using such an ammeter, only go around one wire, not two.

 

[Sponsor]

 

[RichardinTexas]

Such units detect the drop in current when not pumping water vs pumping water. The units get adjusted/calibrated to a pump. If the calibration was on the edge, it could go either way.

You might want to get a clamp-around ammeter to see the pump current in different situations.
When using such an ammeter, only go around one wire, not two.

Thanks. So it is entirely possible for then pump saver to not work if the pump is just hanging in the air like the owner of the well company believes since there would be no change in current between pumping water vs not pumping water.

 

[Boycedrilling]

Don’t know what horsepower your pump is. But for the sake of arguement, let’s say it’s full load amperage is 10 amps. If the pump was in air above the water table, it would only pull about 6 amps.

That is what a Pump saver is doing, is sending the drop in amps when the pump sucks air. Depending upon the brand and model, you can adjust the amperage and sensitivity to the amperage.

Now, I’m only guessing here, but it is possible that your pump technician adjusted your pump saver, trying to get the pump to keep running. It might now be set to where it is t turning the pump off. Again, just a guess my part. However it is an educated guess

This is also what happens with a cycle stop valve. Pump affinity laws are involved. When a centrifugal Pump moves to the left on its performance curve, it consumes less energy, or amps. And yes a submersible Pump is a centrifugal Pump. It is a multi stage centrifugal. As an example, a few years back I installed a 300 hp Peerless lineshaft turbine Pump. It was designed to pump 1,000 gallons per minute from Around 800 ft, if I recall correctly. At the design point it took the full 300 hp. If you were to “deadhead” that pump, it would only draw 150 hp. A 50% reduction in horsepower. However that 150 hp is not producing any useful load. That entire 150 horsepower is being converted into heat.

 

[Reach4]

Thanks. So it is entirely possible for then pump saver to not work if the pump is just hanging in the air like the owner of the well company believes since there would be no change in current between pumping water vs not pumping water.

Presumably the calibration was done when the pump was not hanging in air. However perhaps the cal was not done ideally, or perhaps the setpoint has drifted.

How far down is your water and pump?

 

[RichardinTexas]

Presumably the calibration was done when the pump was not hanging in air. However perhaps the cal was not done ideally, or perhaps the setpoint has drifted.

How far down is your water and pump?

I don't remember exactly but it was around 350' feet give or take when they replaced the metal pipe with pvc 7-8 years ago.

 

[RichardinTexas]

I know they lowered the pump as far as they could when they replaced the pump and pipe back then.

 

[Reach4]

When they next pull the pump, you could have a polyethylene line added to let you measure water depth from the surface. http://crops.missouri.edu/irrigation/installingairlines.pdf Don't use duct tape; use good electrical tape.

I am not sure how you would bring that tubing through a well seal however.

Tubing can be had in 500 ft rolls.

 

[Valveman]

Normally even if the well is being pumped dry, the pump will work for a few seconds or minutes before the well is really dry. I would disconnect the pump saver and run the pump manually. You need to know if the water comes out when you first turn on the pump and for how long, to make sure the pump saver isn't the problem.